A special election for a House district in California left Republicans with control of the seat, while offering scant evidence of the highly energized Democratic electorate that analysts say would be needed to dislodge the GOP from power on Capitol Hill in November.

Fearing humiliation in a race that drew national attention, the National Republican Congressional Committee pumped about $5 million into the race to replace imprisoned former congressman Randy "Duke" Cunningham. But by late Tuesday night on the West Coast, it proved to be money well-spent after former congressman Brian Bilbray won with 49 percent of the vote in the traditionally Republican district. Democrat Francine Busby's 45 percent total barely improved on Sen. John F. Kerry's showing there in the 2004 presidential election.

The results settled Republican nerves, which have been set on edge by months of nearly relentless bad omens, including corruption scandals and dismal poll ratings for President Bush and the GOP leadership in Congress.

For Democrats, it highlighted how difficult it could be to translate generally favorable national trends into tangible victories on the ground. Democratic congressional leaders and operatives said they were heartened at least by the amount of money Republicans spent -- about twice the Democrats' total -- to protect a seat they have previously won with ease.

Even some Republicans privately agreed. But with their side flying into headwinds this fall, the San Diego results showed that Republicans have means at their disposal -- money, skilled candidates and a well-oiled voter turnout machine -- that can be effective in minimizing the impact of an unfavorable environment. The Republican National Committee (RNC) helped organize a voter turnout operation staffed by 150 to 200 volunteers for Bilbray.

"From the beginning, Democrats said this would be a bellwether of what would happen in November," said RNC Chairman Ken Mehlman. "You see a lot of things that are bellwethers, and they indicate Republicans are in position to hold Congress."

Republicans were so nervous about Bilbray late last week that they were already offering reasons to discount the significance of a Democratic victory. Yesterday, it was Democrats who were explaining why a defeat still gave them hope for November.

Democratic Congressional Campaign Committee Chairman Rahm Emanuel (Ill.) said Bilbray's narrow victory in a safe district proved that Democratic hopes for substantial gains remain very much alive. "The message of change is still filled with a lot of jet fuel," he said. "My only hope and prayer is that Republicans take solace in this election so they continue to sleepwalk through it."

NRCC Chairman Thomas M. Reynolds (N.Y.) said the results undermined the Democrats' assertions of a tidal wave in the making. "The results in San Diego show that nothing has happened to alter the notion that House elections are about a choice between local personalities focused on local issues," he said.

The San Diego contest came on a day when eight states picked candidates for November races. In California, Democrats nominated state Treasurer Phil Angelides as their candidate to challenge embattled Gov. Arnold Schwarzenegger. In Montana, state Senate President Jon Tester won an unexpectedly easy victory to claim the Democratic nomination for Senate and the right to challenge Republican Sen. Conrad Burns, who is dogged by ties to convicted former lobbyist Jack Abramoff.

In Iowa, Secretary of State Chet Culver, son of former senator John Culver, won a three-way battle for the Democratic gubernatorial nomination. He will face House Budget Committee Chairman Jim Nussle, who was unopposed, in the tight race to succeed outgoing Gov. Tom Vilsack.

In New Jersey, Tom Kean Jr., son of the former governor, won the GOP Senate nomination and will challenge newly appointed Democratic Sen. Robert Menendez in what could be a competitive contest in November.

In Alabama, Gov. Bob Riley (R) easily dispatched Roy S. Moore, the former chief justice of the Alabama Supreme Court, who was removed from office for placing a monument to the Ten Commandants in the court building. Riley will face Lt. Gov. Lucy Baxley, who trumped former governor Don Siegelman.

But it was the California special election that attracted the most attention in Washington, as an early test of whether immigration, corruption and other issues may affect the balance of power on Capitol Hill. Busby's late gaffe on illegal immigrants -- she made comments in which she seemed to invite them to help her campaign -- in a district highly sensitive to the issue seemed to halt her momentum over the campaign's final weekend and brought private criticism from top Democratic strategists. To take back the House, Democrats will have to defeat a substantial number of experienced Republican incumbents.

More worrisome to Democrats was the fact that Busby's total hardly budged the 44 percent that Kerry won in the district in 2004. "If we can't improve upon Kerry's numbers in these congressional districts in this climate, we've got a big problem," said one strategist, who asked not to be identified in order to give a candid assessment of the results.

For Republicans, yesterday brought a brief respite from bad news. Had the San Diego race gone the other way, it would have triggered near-panic inside a party that has grown increasingly nervous about the voters' sour mood. But Democrats insisted there is no way Republicans can devote similar resources to all the other competitive races in November.

Amy Walter, who charts House races for the Cook Report, said that, at a minimum, Tuesday's outcome denied Democrats a major psychological boost. "This just took what would have been on the front page of every newspaper -- 'Democratic tsunami heading for Washington' -- off the front pages," she said. "You can't overstate how important that is."

Independent analyst Stuart Rothenberg called the results in California "a bit of a downer" for the Democrats because Busby could not woo more independents and Republicans to vote for her. But he said the lessons from California may not apply to districts where House Republicans depend on Democratic votes to win.

Saying that Republicans "can't be naive about what happened," he added, "The Democrats are still searching for evidence the wave is going to hit."

Rhodes Cook, another independent analyst, said that special elections sometimes forecast future trends, but not always, and that he is cautious about reading too much into Tuesday's California results.

Cook said he sees conflicting signs in Tuesday's results in California. Low turnout, he said, was a possible sign that Democratic voters are not as mobilized as party leaders hope. But the fact that a number of House incumbents in California won their primaries with reduced percentages against weak opposition provided additional evidence of an anti-incumbent mood in the electorate, which could hurt the party in power more.